DOCUMENT RESUME ED 204 545 CE 029 456 TITLE Drafting. Advanced Print Reading -- Electrical. INSTITUTION Oregon State Dept. of Education, Salem. PUB DATE 79 NOTE 93p.: For related documents see CE 029 455-457. EDRS PRICE MF01 /PC0$ Plus Postage. DESCRIPTORS *Architectural Drafting: Behavioral Objectives: *Blueprints: *Drafting: *E16ctrical Systems: Electricity: Individualized Instruction: Instructional Materials: *Learning Modules; PostseCondary Education: Self Evaluation (Individuals): Study Guides: *Workboi-oLs IDENTIFIERS Oregon ABSTRACT This document is A workbook for drafting students learning advanced print reading for electricity.applications: The workbook contains seven units covering the following material: architectural working drawings: architectural symbols and dimensions- basic architectural electrical symbols:. wiring symbols: riser diagrams: schematic diagrais: and special applications. Final quizzes for each unit are included at the end of the workbook. Each unit*'. contains an objective, introduction, information sheets, self-assessment quiz with answers provided, and a study guide including references for fdrther information. The materials are illustrated with line drawings. (NC) ****************************,***************11*********44************* * Reproductions supplied by.EDRS are the best that can be Made * froivthe original document. **********J0*****14********Iii*******************************************
Transcript
DOCUMENT RESUME
ED 204 545 CE 029 456
TITLE Drafting. Advanced Print Reading-- Electrical.INSTITUTION Oregon State Dept. of Education, Salem.PUB DATE 79NOTE 93p.: For related documents see CE 029 455-457.
EDRS PRICE MF01 /PC0$ Plus Postage.DESCRIPTORS *Architectural Drafting: Behavioral Objectives:
ABSTRACTThis document is A workbook for drafting students
learning advanced print reading for electricity.applications: Theworkbook contains seven units covering the following material:architectural working drawings: architectural symbols and dimensions-basic architectural electrical symbols:. wiring symbols: riserdiagrams: schematic diagrais: and special applications. Final quizzesfor each unit are included at the end of the workbook. Each unit*'.contains an objective, introduction, information sheets,self-assessment quiz with answers provided, and a study guideincluding references for fdrther information. The materials areillustrated with line drawings. (NC)
****************************,***************11*********44************** Reproductions supplied by.EDRS are the best that can be Made* froivthe original document.**********J0*****14********Iii*******************************************
D afting
Advanced Print Reading I- Electrical
Architectural working drawingArchitectural symbols and dimensionsBasic architectural electrical symbolsWiring symbolsRiser diagramsSchematic diagramsSpecial Applications
U S OEPARTMENT OF HEALTH,EOUCATION & WELFARENATIONAL INSTITUTE OF
EOUCATION
HIS DOCUMENT HAS BEEN REPRO-DUCED EXACTLY A5 RECEIVED FROMTHE PERSON OR ORGANIZATION ORIGIN.ATING IT POINTS OF VIEW OR OPINIONSSTATED DO NOT NECESSARILY REPRESENT OFFICIAL NATIONAL INSTITUTE OiEDUCATION POSITION OR POLICY
. 1 .
"PERMISSION TO HEnRODUCE THISMATERIAL HAS BEEN GRANTED BY
S. Ce&st_e_
TO THE EDUCATIONAL RESOURCESINFORMATION CENTER (ERIC).-
IIXIIUGGOIlta LE Yi3u:n1.)
DraftingArchitectural Working DrawingsPlot PlanFloor PlanFoundation PlanElevationsDetailsInterior ElevationsMechanical Plans
Goat
The student will be able to identifybasic architectural drawings.
Electricians and electrical contractors are constantly working with
structures. Along with being able to understand and read all types
of electrical drawings they must be able to fully understand and read
the architectural drawings they will be using.
It is suggested that those persons dealing in depth with architectural
drawings also work in "advanced blueprint reading, construction" for a
more indepth study of architectural working drawings.
1n.,,,,,Drima Ion
ARCHITECTURAL .:KING DRAWINGS
The term "working drawings" or "construction drawings" refers to aset of drawir4s for a structure. They include all the drawings
necessary for construction of a building. The entire set usuallyconsists of vi...-ious types of drawings for different purposes.
A typical set of working drawings for a single-family residence mightconsist of: a floor plan, a foundation plan, elevations, sectional
details, and a plot plan.
As the structure becomes more complex, the number and complexity ofthe drawings increases. A small commercial building may haveadditional drawings for mechanical and electrical systems, or moredrawings showing the details for construction of specific parts of
the structure. A large office complex might have a many as 100drawings to show how the structure is to be completed.
In most cases, for small structures, the electrical plan is quitesimple and may be part of another drawing. To save time, theelectrical plan may be "overlaid" on the floor plan of a structure.
1. PLOT PLAN
An important part of the working drawings for a structure isthe plot plan. It describes the property on which thestructure will be constructed, the position of the structureon the property, access to the property from streets or roads,existing features of the property and services to the structure.
An example of a plot plan is shown below.
U
SL op
219'
WELL
,E L.103.4'
-0)Ch
EL. 100.1'
O.0cn
f-REPLACEMENT,-DRAINFIELD
',AREA
.1
TESTPIT-
1000 GAL.EPTIC TA PRO OSEDS NK
,re0,
83 BORM
M E L.I05.4,s
HOUSE
-4--TREE o
LINDEN LANE(PROPOSED)
WELL ONI ADJACENT LOT
DRIVEWAY
-EL.I04.1'
PLOT PLAN
6
I
2. FLOOR PLAN
The floor plan contains the information most needed forconstruction of a building. It shows the layout and sizesof rooms, placement of doors and windows, locations of stairsor steps, location and site of cabinets and appliances. All
the necessary dimensions for locations and sizes of partitionand bearing walls and a variety of other items of information.
The floor plan is actually a section through the walls of abuilding, shown in plan view.
PLAN VIEW
6
r-
FLOOR PLAN
An example of a floor plan is shown below.
IV:.4 11. e . . , r I
*t fr.,.- -!. -
LI VI NJC.1 OCC:4.4'
4
417:r.r 4-
't.
_ -
; _ sw .t?j1101 rid re
V
I I
1
9 4441Gla I400. 4.0 .4rittrowC . rMAW M.
tY411 Ibt.A44 014. VOW.
8
korner. Am namowe 174'A.L. litedaelr A
. . .
S
a
3. FOUNDATION PLAN
The foundation plan may also include the basement plan. Itconsists of another section shown in plan view. The sectionis taken just below the first floor.
Foundation plans show the concrete foundation, footings, slabs,girders and posts, air vents, access doors and dimensions forsize and location. The mechanical system may also appear onthe foundation plan.
0
--;,PLAN VIEW
r_ MOD MEM WWI W8.0 1
9
4. ELEVATIONS
Elevations show the exterior sides of the building as they wouldappear viewed from the front, right side, rear and left side.They may be labeled in this manner or as they would appear lookingat the four points of the compass: north, east, south, and west.
LEFT(WEST)
FRONT( SOUTH)
REAR(NORTH)
RIGHT( EAST)
FRONT RIGHT LEFT REAR( SOUTH ) ( EAST ) ( WEST ) ( NORTH)
10
An example of a front elevation is shown below.
=r1.1-11-11= 1
111111111 11111111111 mmr,a
,2
11
5. DETAILS
Detail drawings show the particular techniques and materialsrequired to construct various parts of a building. They mayinclude framing details, concrete details, sections, floorframing plans, roof framing plans, beam details, column detailsor any number of other construction areas which may rewiremore information than is contained on the floor plan.
Sections may be taken at any point through the building. Theymay be full sections, offset sections or broken-out sections.
SECTION VIEW
TYPICAL SECTION
12 13
Some examples of common details are shown below.
235 COMP SHINGLE.4
1/2°CDX PLY SHTG
12
rx(RIDGEliteCOLLAR
2'x6" RAFTERS 16"*.c.
1'x6" FASCIA
neSTUDS16'o.c.
218"HEADERTERMITE SHIELD--
G.I. GUTTER
TGDX PLYSH
EXT. PLYWOOD
RADE
CONC WALLSMe FOOTINGS
MTL TIE
. lirkl(rx12° CONC FOOTING
STUD
BOTTOM PLATE
SLEEPER OR FURRING
AIR SPACE
FACE BRICK
INSULATINGSHEATHING
4(.1.
RIGID INSULATION
KEY
-VAPOR BARRIER.
Poured footing & foundationfor frame veneer constructionwith a slab floor.
413
13'it
6. INTERIOR ELEVATIONS
Interior elevations show cabinet wails, fireplaces and specialwalls as they would appear from inside the rooms. Some examplesare shown below.
2"
24"
HL--FLAGSTONE HEARTFV-1 12"
FIREPLACE ELEVATION
SOFFIT
I I
I I
MEM
MOM OEM
24"
14
7. MECHANICAL PLANS
Mechanical plans include electrical plans, plumbing plans,and heating, ventilation and air conditioning plans. Theymay be drawn over (superimposed) on the floor plans, foundationplans, or basement plans. If the mechanical systems becomecomplex enough they are drawn separately or combined on asimplified floor plan or foundation plan.
FAMILY ROOM
1?!
I 6
INSTRUCTIONAL LEARNING SYSTEMS
A ifDirections: Complete the following sentences.
1. The plan describes the property on which
a building will be constructed.
2. The plan shows the layout and sizes of
rooms.
3. Theconcrete slabs.
4. The front shows the exterior of the building
as it would appear from the front side.
plan shows the concrete foundation and
5. show portions of the building as
if they were sliced through.
6. eleveations show the inside walls
and cabinets in a building.
7. plans show electrical, plumbing,heating, ventilation and air conditioning systems or circuits.
Framing members, walls, cabinets, and other features are depicted on
architectural drawings by using a series of standard symbols. These
symbols help simplify the drawings and increase readability.
The dimensioning techniques used on architectural drawings differ from
those used on mechanical drawings. These differences may be very
subtle, but it is important that you understand and recognize them.
2019
Imo I nut,. s
Information1. FLOOR PLAN SYMBOLS
Doors, windows, walls, cabinets, closets and stairs are allshown on the floor plan with symbols. These symbols describesize, type and locations of the features.
Walls:''
Fill in the walls onthe back. Very black.
Standard exterior wallsdrawn 6" thick.
Standard interior wallsdrawn 5" thick.
Draw 8" interior or exterior wall behind atoilet to allow for soil pipe plumbing.
Walls may be blackened in or one of the following symbols maybe used.
NO SYMBOL la-
IPPP;
or0WOOD BRICK
Doors
Allow about 3"-,11
Sill Outside
Inside
Uoor should swing intothe room and against the wall.
INTERIOR DOOR
EXTERIOR DOOB
Allow about 3"
No SillNo
Door should swing into the
room and against a wall.
SLIDING CLOSET DOOR
BIFOLD CLOSET DOOR
21L12
SLIDING GLASS (PATIO) DOOR
POCKET SLIDING DOOR
4211111=ir--
Outside
1111111PInside
There are many other door symbols, but these are the most common.If you need others, see your references.
Windows:
SLIDING WINDOW
There is a sill on
the inside
and on the outsideof windows.
CASEMENT WINDOW
22 23
DOUBLE HUNG WINDOW
Cabinets & Fixturei:
Upper cabinets hidden lines12"
Double eircBase cabinets
24"
The, size of your range and refer may vary
but you can draw them at 30" wide.
1' min. betwitiriRange & Refer
dfik-nk---7
V*01n, T !etis tandard
..., : t.. -It y ,
OlOk symbol. .
Closets:
Rod & Shelf
A minimum single wall walk-in closet might be 5'0" wide x 5'6" long,and a minimum double wall could be 7'0" wide x 5'6" long.
Stairs:
12'0"
N
13 R
HRA IL
Stairs in plan only show the direction and number of risers and walllengths.
MISCELLANEOUS SYMBOLS:
HOT WATER HEATER
LAUNDRY TUB
F A.
FUR N.
FORCED AIR.
FURNACEWASHER aDRYER
26
ARCHEDDOORWAY
25
2. DIMENSIONS
Architectural dimensions are always given in inches for measure-
ments up to six feet and in inches and feet for measurements over
six feet.
The dimension line is not broken as it is in mechanical drawing
and the dimension is placed above the dimension line.
121- 0"
Dimension lines may be capped with arrowheads where they meet theextension lines, or they may be like this:
8*-8"
26
Aligned dimensioning is used so that the dimensions read fromthe bottom and right side of the sheet.
o-0
31
The overall dimensions on frame construction are given to theoutside of the stud frame, because that dimension is usedfirst, before the sheathing and other wall covering is applied.
In this wall frame structure, dimensions of interior walls,windows, and doors to the centers.
17'.O"
4f4"
81-6"
49-3" 4'4" 45-3"
You don't leave one dimension blank as you might
do in mechanical.
27
When you dimension concrete or masonry'construction as in a
residential basement, then you can do it like this:
NNW
81.8" T8"
10"..1
s ..ss,. .
8'-8" Jo.2"
In wood frame, the window and door size determines the size ofthe opening and may be slightly oversize, but in concrete thesize is critical, hence the difference in dimensioning.
3. SCHEDULES
Schedule Setup
A schedule is a chart of materials or products with sizedescription, quantity, and any other information neededto construct or finish the building.
Schedules aid a drawing by keeping the drawing clear ofunnecessary notes. Items that can be keyed to the draw-ing and placed in a schedule, such as windows and doors,should be considered. There are many different ways toset up a schedule; here is a simple example:
DOOR SCHEDULE
Key Quant Size Description
1 2 3'0" x 6'8" Solid Core
2 6 2'8" x 6'8" Hollow Core
3 4 6'0" x 6'8" Bi-Fold Closet
4 2 8'0" x 6'8" Glass Sliding - Safety
5 1 2'8" x 6'8" Pocket Sliding
This example gives only the minimum information, otherstell material and remarks about the product.
s:
10"
28
n
41 Schedule Key
The doors and windows must be keyed to the schedule. This
can be done by labeling the doors with a number and thewindows with a letter. You can also use different geometricfeatures; like this
Or, you can consider labeling windows with a (W) and doorswith a (D), like this
Look at Figure 1.
30
29
INSTRUCTIONAL LEARNING SYSTEMS
I S IfAssessmentDirections: Identify the fol 1 owi ng symbols:
Since most electrical plans are those used with architectural-typedrawings, the main emphasis will be on symbols used in this type ofelectrical plan.
Unlike the symbols used in most electronic schematic diagrams, thesymbols for architectural drawings descr4be a total piece of hard-ware or a unit of electrical components. Most of the symbols aresimple; for example, circles or squares, with an identifying letteror letters to help distinguish one symbol from the next.
The exact purpose of the drawing will determinethe type of drawingused. Several types of electrical drawings will be discussed insubsequent modules. However, the symbols will remain relativelyunchanged from one type of drawing to another.
INSTHUI; I IONAL LtArtivitliu OTOI CIVIC
Information. LIGHTING SYMBOLS
There are two common types of lighting fixtures used in moststructures. The incandescent and fluorescent lamp are themost frequently used fixtures in most residences and lightcommercial buildings. The basic symbols are shown below.
0INCANDESCENT LAMPCEILING MOUNTED
INCANDESCENT LAMPWALL MOUNTED
FLUORSCENT STRIP
FLUORESCENT FIXTURE
A light fixture that is recessed in the ceiling would havea dashed line indicating the basic shape of the fixture,for example:
Some of the other lighting symbols are shown below.
II I :
(2)P S. FP. S.I I
1I 1
1
WALL MOUNTED CEILING MOUNTED t- I-I
LAMP Me PULL LAMP W/ PULL I I
SWITCH SWITCH I 1
rSUSPENDED; LIGHTEDCEILING PANELS
34 .e.!
2. SWITCH SYMBOLS
The basic switch symbol for a typical lighting circuit ismerely the letter "S" placed on the plan in the position wherethe switch is to be located. Switches that control more thanone circuit or that work in conjunction with other switchesare indicated by the number "3" or "4" placed by the letter "S."
S S3
BASIC SWITCHSYMBOL
S4
THREE - WAY FOUR - WAYSWITCH SWITCH
Some of the other switch symbols:
SP ST
SWITCH WITH APILOT LIGHT
TOGGLE SWITCHWITH THERMALCIRCUIT PROTECTOR
(FUSED)
Other identification letters may be used with a table or legendto indicate their meanings.
3. ELECTRICAL OUTLETS OR RECEPTACLES
The basic electrical outlet with two receptacles is knownas a duplex receptacle. The symbol is shown below.
DUPLEX RECEPTACLE
Modifications to the basic duplex receptacle symbol includethose for waterproof outlets, switch and receptacle combinationsand receptacles with one outlet controlled by a switch.
01,3 OSWEATHERPROOF COMBINATION WITH SWITCH
3635
4. BASIC SWITCHING ARRANGEMENTS
A dashed line from the switch to the receptacle or lamp fixtureindicates the basic wiring for these fixtures.
(1)WM= WM
0111 0
SINGLE. SWITCH SINGLE SWITCH ANDAND LAMP TWO LAMPS
VI
SWITCH AND RECEPTACLE
0 .... `" .... ........ *...
*Of
Ch ff.
cn
TWO THREE-WAY SWITCHESAND A SINGLE LAMP BY THREE SWITCHES
SWITCH AND WALL MOUNTEDLAMP
TWO LAMPS CONTROLLED
5. MISCELLANEOUS SYMBOLS
There are many other symbols used on electrical plans.are shown below.
RECEPTACLE, MOUNTEDFLUSH WITH FLOOR
EY BUZZER
POWER OR LIGHTPANEL
0 SPECIAL OUTLET(IDENTIFY WITHLETTERS)
0
TELEPHONE OUTLET
MOTOR CONNECTION
CIRCUIT BREAKER
6. ABBREVIATIONS
CB - Circuit Breaker
AFF - Above Finished FloorCSP - Central Switch PanelMDP - Main Distribution PanelGd - GroundedNL - Night LightR - RecessedWP - WaterproofM - MotorF - FanTEL - TelephoneBUS - BuswayCOND - Conduit
All electrical diagrams use symbols to indicate components,
contacts and switches. These symbols simplify the diagrams and
provide an expeditious means of showing electrical components.
Standards for symbols have been established by the American National
Standards Institute. Those standards are reflected in this module.
Atx
43
Information1. SWITCHES, CONTACTS AND RELAYS
Electrical wiring diagrams usually contain several switches or
switching assemblies. The symbols used in single-line wiringdiagrams show each switch and contact in relation to the circuit
it controls. The basic switch symbols are shown below.
SINGLE -THROWSWITCH
KNIFE SWITCH
SELECTORSWITCH
0DOUBLE-THROWSWITCH
0 0PUSH BUTTONSWITCH
O OroDOUBLE-POLEDOUBLE-THROWSWITCH
The switches shown above, with the exception of the selectorswitch, are shown in an "open" position. In each case, theswitch is "closed" if the symbols are touching, for example:
SINGLE-THROW(CLOSED)
0- 0PUSH BUTTON
(CLOSED)
As you can see in the switch symbols, the contact is the open-circle portion of the symbol.
4544
Disconnection type couplings, such as plugs and jacks, have aspecial symbol which indicates how the connection is made.
PLUG JACK
Together, these symbols indicate a separable connector.
When used in multiples, the symbols indicate several plugs and
jacks in one piece of hardware.
The letters are added for identification.
Another symbol that indicates a multiple connection device is
shown below.
le
45
Relays are shown as a square with the letter "R" inside or asa rectangle with an identifying symbol on one end.
R
Specific relay symbols:
evi
[o I
N1+1 1
Other letters may be used toidentify special characteristicsof the relay:
AC - alternate currentD - differential
DB - double biasedEP - electrically polarizedFO - fast operateFR - fast releaseP mangetically polarized
SO - slow operateSR - slow release
Alternate current
Fast operate
Fast release
Magnetically polarized
Slow operate
Slow release
46
2. CIRCUIT PROTECTORS
Circuit protectors are normally fuses or circuit breakers of
various types. The basic symbols are shown below.
CIRCUIT BREAKER
OR
FUSES
Note: Sometimes the symbol for a thermal element is used to
indicate a thermal-overload fuse.
THERMALELEMENT
Some of the modified symbols are:
HIGH-VOLTAGEFUSE
OIL-TYPEHIGH-VOLTAGE
FUSE
3. CONDUCTORS
Electrical transmission paths are shown in a variety of toys,
4_ depending on the type of drawing in which they are used.
Single-line drawings use symbols that would indicate one, two,
three or more conductors or wires. Qualifying letters may
be used to indicate special characteristics of the conductor or
wire sites.
BASIC CONDUCTOR CONDUCTOR SYMBOL
SYMBOL FOR POWER
47
S gap .10Conductor symbol forarchitectural drawings (howsonly circuit control and doesnot indicate actual path ofconductor).
3-N0.4AWO
IN I I/2" CONDUIT
Conductor symbol with anote indicating threewires, size no. 4 (AmericanWire Gage), in a 1 1/2 inch
diameter conduit.
In very complex electrical drawings, it may be necessary to
indicate the direction of a conduit or conductor turned. This
helps trace circuits.
0WIRING OR CONDUIT
TURNED UP
WIRING OR CONDUITTURNED DOWN
It may be necessary to indicate whether a conductor is concealed
or exposed. The symbols below show how this is indicated.
WIRING CONCEALED INCEILING OR WALL
M/MIIMI
WIRING CONCEALED WIRING
IN FLOOR EXPOSED
In some drawings, conductors are placed in ducts or "busways."
The symbols may vary slightly; but, generally they look like
those below.
WIRING DUCT OR TROUGH
WIRING DUCT OR
BUSWAY
48 49
4. POWER DISTRIBUTION SYMBOLS
Because of the simplicity of some electrical diagrams, it is
not necessary to show detailed symbols of each electrical
component. Therefore, the symbols are simplified to squares
or rectangles with letters to describe the electrical part.
These parts are referred to as circuit elements. Some of these
symbols are shown below.
CB Circuit Breaker
I R I
PE
FL
I PS I
T
RG1 Recording Unit
Relay DIAL Dial Telephone
Photoelectric Cell biall Teletypewriter
Filter fall Amplifier
Power Supply
Transformer
Wel Microphone
gar-1 Loudspeaker
Motor and generators are also simplified symbols.
Motor Motor w/horsepowerindicated
Generator
Metering devices are circles with designation letters inside
the circle.
C-.) Ammeter
(g) Decibel Meter
(E) Frequency Meter
(E) Ohmmeter
(E) Oil Pressure (E) Watt Meter
PH Phase Meter
0 Temperature
Volt Meter
50
0 Watt -hourMeter
49.
A few symbols remain independent of the drawing type. They
are the same for all electrical and electronic wiring diagrams.These symbols are shown below.
RESISTOR
BATTERY
CAPACITOR
TERMINAL
BOARD
51
TRANSFORMER
IGROUND
50
INSTRUCTIONAL LEARNING SYSTEMS
SelfAssessmentDirections: Identify the following electrical symbols in the
space provided. Check your answers with those on
the next page.
(I) (2)
(3) -crSp.--. (4)
(7)
0 0
(9) (10)
(13) ---V\AA--
(IS)
(12) C)1
(14) -1
(16)
AnsWers to Self Test
(1) Single-throw switch (2) Push-button switch
(3) Knife switch (4) Relay
(5) Circuit breaker (6) Fuse
(7) Three-wire conductor (8) Wiring turned dewn
(9) Exposed conductor (10) Power supply
(11) 1/2 Horsepower motor (12) Volt meter
(13) Resistor (14) Capacitor
(15) Transformer (16) Battery
52
Study Guide
For Further Information:
IEEE Standard and American National Standard, Graphic Symbols forElectrical and Electronic Diagrams, 1971, ANSI V32.2.
Electrical and Electronics Drawings, Baer, 1973.
National Electrical Code, 1975 ed.
National Electrical Code Blueprint Reading, Gibert, 1974.
Power riser diagrams are one of the more frequently used types of
electrical diagrams for building construction. These diagrams show
the relationship of the electrical components and how they are.
connected. Riser diagrams are simple to draw and easily read.
111111Wil
Inform tion1. BASIC COMPONENTS
Most riser diagrams show the service entry, meter, and power
distribution panel as their basic components.
The service entry may be in the form of a roof mount "weather-
head" or an underground service. The symbol that indicates a
weatherhead is shown below.
The service meter is usually mounted on an exterior wall below
the weatherhead.
The power distribution panel may be a simple 200 amp service
or a very complex panel for an industrial or commercial
building. However complex, the panel is usually labeled or
otherwise identified, and power panel schedule is used to
identify the branch circuits.
56
2. POWER PANEL SCHEDULES
The power panel schedule is used in conjuction with the riser
diagram to supply additional information for the electronic
contractor.
The schedule usually includes a number identifying the circuit,
circuit breaker or fuse amperage, wire size, electrical load
data and remarks.
SCHEDULE FOR POWER PANEL "A"
Main Lugs Onl 120/240V,,_ _____
CKT NO. CircuitBreaker
WireSize
Load Items Fed
in KW or Remarks
Trip Pole
1 20 1 12 1400 Lights
2 20 1 12 1400
3 20 1 12 1400
4 20 1 12 1400
5 20 1 12 1400
67
2020
1
1
12
12
14001400
8 20 1 12 1400
9 20 1 12 1400
10 20 1 12 1200 Receptacles
11 20 1 12 1200
le12 30 3 10
13 30 3 4
14
1516
17
1
57
3. CONDUCTOR AND CONDUIT IDENTIFICATION
One of the primary purposes of the riser diagram is to show
conductor sizes and conduit sizes. The actual labeling may
vary, but the information is basically the same.
4- 3/0THWCONDUCTORSIN 2 1/2" CONDUIT
Wire sizes are given according to the American Wire Gage Standards.
Conduit.sizes are given in diameter of tubing.
4. TERMS
Often the readability of any drawing depends on the proper use of
technical terms and an understanding of these terms on the'part
of the reader. Therefore, some of the terms commonly used on riser
diagrams are given below.
Branch Circuit - The circuit between the final circuit,protection
device and the outlets.
Feeder - The conductors between the service equipment and thebranch circuit protection device.
Receptacle - A contact device for the connection of a single plug.
Service - The conductors and equipment used to deliver electricity
to the wiring system of a structure.
58
5. THE BASIC RISER DIAGRAM
Shown below is a riser diagram for a small commercial building.
3 PHASE4 WIRE
120/208;37
ROOF-k
60ALsi,, AIR COND.
UNIT 1
FLOOR-NI.
3-N2 4 AWGIN I I/2" CONDUIT
6 "x 6 "x 4'WIRE TROUGH
PANEL
C T
B
CAB.
1 PANEL
C
In the diagram above, the feeder lines run from the weatherheadto a current transformer panel (CT) and the main power distributionpanel "B." There's an air conditioning unit on the roof thatrequires 240 volts, so a 1 1/2" conduit is connected from panel Bto the unit via a disconnect device marked "N." This device is amain power disconnect for the air conditioner.
Panel "C" is an additional power distribution panel for some 240volt equipment in the building. It is connected to panel "B" bya wire trough. Two booster transformers provide the additionalvoltage to panel "C."
59
INb I PlUt;11UPIAL LCAS11VinsU otos cnno
Self
Directions: Identify the components of the power riser diagram below.
4- No. 2I I /4" COND.--t)
2
3-No. 1211/2"
COND.
2nd FLOOR
0.0
MAINDIST.PANEL2500 A
2TRANSFORMER
I/ fl
UNDERGROUNDSERVICE
I o...._4.F..00.1L___2
L = LIGHTING PANELP = POWER PANEL
EM= EMERGENCY CIRCUIT
6-4" CONDUITS BY CONTRACTOR
FEEDER CONDUCTORS BY POWER CO.
(1) How many branch circuits are shown?
(2) How many three-wire conductors are shown?
(3) What diameter conduit runs from the main distribution panel to theemergency circuit panel?
(4) How many amps is the main distribution panel rated for?
(5) Instead of a' weatherhead, what type of service equipment is shown?
Continued
60
(6) How many lighting circuit panels are shown?
(7) How many secondary power panels are shown?
(8) Name the device connected to the emergency circuit panel by 3No. 12 conductors in a 1 1/2" conduit.
ReLea (8) !om4 !aa.444 (9) !punoZaapun (g)
!sdme 0052 (t) Put Z/L L (E) teAtj. (Z) !XI.S (0 :SJOMSIN
Study Guide"Va.m11...
'CP
For Further Information:
Electrical and Electronics Diagrams; The American Society ofMechanical Engineers, ANSI V14, 15, 1969.
Electrical and Electronics Drawings, Baer, 1973.
National Electrical Code Blueprint Reading, Gibert, 1974.
Schematic diagrams are used for assembly, maintenance and analysis
of electrical circuitry. They show components in their properrelationship to other components and circuit flow by using graphic
symbols for the components. The circuit represented on schematic
diagrams is the "theory" or relational circuit not the actual
wiring or connection diagram for that circuit.
Schematic diagrams are used in control circuits, installation
circuits and power distribution circuits to show the component
and conductor arrangements for those circuits.
uJ
64
k.
111119.0 I i II OVOS tu.
Information1. BASIC COMPONENTS
Schematic diagrams are made up of component symbols and
conductors. The electrical 4ymbols covered in a previousmodule will be used to indicate components in the electricalschematic diagram.
The exact composition of the schematic diagram will dependentirely on the circuits and hardware being shown.
Electrical schematics normally show switching circuits or powerdistribution circuits. Therefore, the number of differentsymbols shown in one drawing will be few.
Schematic diagrams generally follow the circuit, signal, ortransmission path from input to output, source to load or inthe order of functional operation. For example, a schematicmight show the circuit flow from a battery to a lamp.
Conductor paths are shown as connector or crossing over eachother by the symbols shown below.
CONNECTING CROSSING OVER
2. MECHANICAL LINKAGES
It is sometimes necessary to show mechanical functions such asrotation, braking or clutching as part of an electrical circuit.The mechanical components are linked to the electrical componentsby using a dashed line. An example is shown below.
100RPM
- - -E - --CLUTCH
T I
65
3. TERMINALS
Terminals of components are normally numbered according to
numbers that already exist on the component itself or
arbitrarily from some reference point on the component. An
example of terminal identification is shown below. Notice
that the terminals are shown in the schematic in a different
arrangement, than they actually appear on the component. The
symbol for this component determines the terminal locations,
not the component itself.
I 0 2 SCY'
40 5
3
Os
Symbol for a double-pole, double-throwswitch as shown on aschematic.
3 0 0 60
2 0 WO 5
I 0 0 4
Actual componentviewed from rear
4. CONDUCTOR IDENTIFICATION
On some schematics it may be possible to describe the actual
wiring of the components instead of including a separate
wiring diagram. However, it is usually customary to have both.
Conductors may be identified for, wiring by color code, number,
letter, or geometric symbol. In most cases, the easiest system
to read and understand is the color code. Each wire or
conductor is identified by a color code and its terminal or
contact connections can be traced by following that particular
color throughout the circuit. An example of color code marking
is shown below.
TIG
R
66
CONDUCTOR COLOR CODE ABBREVIATIONS
Color Code Abbreviations
Black 0 BK
Brown 1 BR
Red 2 R
Orange 3 0
Yellow 4 Y
Green 5 G
Blue 6 BL
Violet 7 V
Gray 8 GY
White 9 W
5. SWITCH POSITIONS
On schematic diagrams it may be useful to identify the circuitcontrol function for each position on the switch, for example,"on" and "off." For more complicated switches, the functionmay be shown on the drawing itself or on a table or legendsomewhere else on the drawing.
S I OFF
30 120 v
40 240 v
50 120 v REG.
Functions shown onsymbol in aschematic diagram.
S I VOLTAGE CONTROL
FUNCTION TERM
OFF I -2
120 v I -3
240v I -4
120 v REG. 1-5
Table showing switchfunctions
6. COMPONENT IDENTIFICATION
Components in an electrical schematic are identified by a letterand number. The numbers are assigned sequentially for similarcomponents, and read from left to right and top to bottom. Forexample, the first transformer in a circuit viould be identifiedby the letter "T" (transformer) followed by the number "1."
11
The particular size of the component or rating may also be
shown. Such as ohms for resistors and volts for power supplies.
100
OHMS
BTI
6 VOLT
COMPONENT IDENTIFICATION LETTERS
A = Antenna
BT = Battery
CB = Circuit Breaker
F = Fuse
HR = Heater
L = Inductor or Winding
DS = Lamp
C = Capacitor
B = Motor
Y = Oscillator
K = Relay
S = Switch
TB = Terminal Board
T = Transformer
R = Resistor
7. EXAMPLES
An example of a basic schematic diagram is shown on the next
page.
Lv41
68
CBI
L IPI JAI
CB 2
INPUT L 2 P_2 J2 ei-N
C B 3P3 J 3
L 3d )
B I
TICONTROLTRANSFORMER
STOP F I
CI
The designations Ll, L2, and L3 are input leads to this circuit.
The circuit shown is part of an industrial control system and
the contacts and leads for Ll, L2, L3 are shown on other
schematics for this system.
Notice the rocker type start-stop switch (S1). The disconnects,
at P1 through P3 and Jl through J3 are fot disconnection of the
circuit from the motor and protection box which houses the
circuit breakers.
70
K I
OVERLOADRELAY
Another simple schematic diagram of a control circuit is shown
below.
TO MOTOR
TI
CONTROL CIRCUIT SCHEMATIC
S01 STOP
STAIIT
-0
1"
Contactors
M Main ContactorA = Accelerating Contactor
TR = Timing Relay1CP = Auxiliary Control Relay2CR = Auxiliary Control RelayOL = Overloan RelayTC = Time Closing Contact
The symbol shown for a contactor and relay ha:, several meanings.
The table shown identifies the characteristics of that component.
71
70
4
C
INSTRUCTIONAL LEARNING SYSTEMS
SelfAssessmentDirections: Provide the answers requested for the following.
Check your answers with those on the next page.
(1) Complete the diagram to indicate that conductor one is connectedto conductor two.
CONDUCTOR - 1 ...5\414 CONDUCTOR - 2
(2) Complete the diagram to show that the gear reducer ismechanically linked to Motor 2.
GEARREDUCER
(3) Trace the black wire from terminal two of the motor to theterminal board. What is the number of the terminal it isconnected to? . (See diagram on next page.)
MOT
L I0
R R 1
BR BSI
CI TB1
S2
I0
OL 2
010203040506
71
(4) Use the proper letter to identify the following symbols. Place
your answer in the blank below the symbol.
(c)
(e)
(d)
(f)
(g) 1 I F---- (h)
.9 (0) tj (4)
eo (.1t) le (at) s (pr) ti (Pt) 3 (0) II (Pt) z (E)
:suamsuv
72
For Further Information:
Electrical and Electronic Diagrams, The American Society ofMechanical Engineers, ANSI V14.15, 1969.
Electrical and Electronics Drawings, Baer, 1973.
National Electrical Code Blueprint Reading, Gibert, 1974.
Electrical Blueprint Reading, Traister, 1975.
ILS Drafting: Electrical/Electronics, article 26.70
FINAL QUIZ IS AN INDUSTRY DRAWING!
74
73
4 0
ink-M=041AL Lamninc yamo
DraftingSpecial ApplieMionsPower DistributionIndustrial Control CircuitsAlarm CircuitsTelephone Switching Circuits
4VV".4'701M
Goal:
N.
The student will be able to readof the special applications of elcct'icaldrawings.
There are many typ.n of electrical drawings that don't fall into
any' particular crogories. They are drawings that may use some form
of block diagraz, like that used with riser diagrams, or they may be
more on the ordv of the schematic diagrams.
Special circuits may include the control circuit for a fire alarm
system or an electrically controlled sprinklerlYstem, or they may
be the malA poser distribution circuits of power substation. In
any case, they all use some of the symbols and techniques discussed
in previous aiodules, so they should not be considered a new type of
drawing.
75
I PIST IIUNAL LtAnNi mu oval Lavou
Inform tion1. POWER DISTRIBUTION
In general, power distribution circuits include all electrical
drawings. However, for simplicity, the circuits will discusswill:be those dealing with major power supply and distribution
circuits for a structure.
Power distribution circuits are generally drawn in a simplified
block-type diagram, or with a combination of schematic component
Umbols and block symbols. For example, plugs, fuses, circuitbreakers, transformers: and relays may all use a schematic typesymbol, while motors; generator and control panels may use circles
or rectangles. The example below shows a portion of a circuit.
Notice the difference in the symbols.
TOSUBSTATION
fmMOTORS
PANEL
MOTOR
EDEN
Power distribution circuits may be accompanied by severalelaborate tables or schedules for the circuitry in the controlpanels or identification of cables and conductors in massivewiring troughs.
A typical power distribution circuit for an industrial plant is
shown on the following page. The diagram looks quitecomplicated at first glance; but once it is studied for a momentand broken down into small parts, it becomes very simple.
7677
MOTORCONTROLS
..""(
ti480 v.ArrT
it'
I
t
TYPICAL INDUSTRIAL POWER
DISTRIBUTION DIAGRAM
OUTSIDE BUILDING
.44_1 UTILITY SERVICE22.9 -138 Kv.
4-10ILTYPECIRCUIT BREAKER
f
4160 VOLTS1111111
FEED
480K
I IIDEP*Ir.;
FEED
I11)
MOTORF E R
METERING aRELAYS
CIRCUITAIRTYPE
BREAKERS
YY 1)1,1)
MOTORCONTROLS
INSIDE BUILDING
vo
GENERATOR 71. TIE. V48v0
Y)
1; 7)III illMOTOR
CONTROLS
TOSUBSTATION
2. INDUSTRIAL CONTROL CIRCUITS
An electrical controller is a device or g, 4 of devices which
governs or controls electrical current del .ered to electrical
components. They may include components such as circuit breakers,relays, motor-circuit switches and contactors.
Motor-circuit switches are used to interrupt power or current to
a motor or starter during overload situations.
A contactor is used to make frequent or repeated on-off type
switches of current to a component.
Control circuit functions are very basic, but most essential
in electrical circuits. They are: starting, protection, running,
speed regulation and stopping.
Some of the basic circuits for control are shown below.
SELECTSWITCH
Single knife switch
Automatic pressure switch
Push button switch
Momentary contact pushbutton
Selector switch Z wireand push button
78
3. ALARM CIRCUITS
Alarm circuits for fire, security and warning systems are another
special application of electrical drawings. In most cases, the
simplicity of alarm circuits allows the use of riser diagrams to
explain the circuit. All alarm circuits need to have an emergency
circuit to supply power during emergency power outages. Emergency
panels are normally designated as "EM."
In a large building, there may be several separate circuits and
many alarm devices. The exact location of each device must be
shown in a schedule or table and not on the drawing. However,
if the building is small or moderate in size, the location of the
devices can be shown on the drawing. A riser diagram for an
alarm system is shown below.
CORR. C-2 CORR. B-2 CORR. A-2
CORR. CORR. CORR. CORR. CORR. CORR.
FRnM POWERA B C C - I .'BA A-I
PANEL C
11CONTROLPANEL
3 CONNECTORS TO AUX.POWER SYSTEM INMAINT. ROOM
SECURITY ALARM CIRCUIT
5 CONNECTORS TOSECURITY ALARMSYSTEM IN SMITHBLDG.
Notice that this system has a backup circuit connected to thesecurity system of another building.
79
4. TELEPHONE SWITCHING CIRCUITS
Since most telephone switching circuits have incorporatedelaborate integral electronic circuits, the reason for dis-
cussing the old style relay systems is that they are still
used for some intertelephone circuits or intercom circuits.
A simple telephone switching circuit, in riser diagram form,
is shown be44.
RM RM RM RM RM RM
202RM
204
201RM
206
203RM
208
RM207
RM RM
210 1 1212
RM RM RM
1 Nam mil a. im 1I st FLO
105
1LI-INTERCOML2 CONTROLL3-- PANEL
SWITCHBOARDOFFICE
MOTEL TELEPHONE SWITCHING CIRCUIT
81
80
INSTRUCTIONAL LEARNING SYSTEMS
SelfAssessmentDirections: Complete the following questions. Check your answers
with those on the next page.
(1) A circuit that shows incoming electrical current from a powerplant and all the dispersal circuits within a building wouldbe a
(2) Starting, protection, running, speed regulation and stoppingare all functions of an industrialcircuit.
(3) Devices used to interrupt power to a motor or starter during
overload situations are
(4) A device used to make frequent or repeated on-off switching ofcurrent to component is a . .
(5) circuits need to have an
emergency circuit to supply power during emergency power outages.
Ur,
.81
Answers to Self Test
(1) Power Distribution Circuit
(2) Control Circuit
(3) Motor-Circuit Switches
(4) Contactor
(5) Alarm
FINAL QUIZ IS AN INDUSTRY DRAWING!
Of)
82
tudy Guide
For Further Information:
IEEE Standard and American National Standard, Graphic Symbols for
Electrical and Electronic Diagrams, )971, ANSI V32.2.
Electrical and electronics Drawings, Baer, 1973.
National Electrical Code, 1975 ed.
National Electrical Code Blueprint Reading, Gibert, 1974.
